The present invention relates to a protective door shield and mounting for a lock and, more particularly, to such a device that is usable with a variety of locks requiring different arrangements of apertures in the sides of the door.
The installation of door locks conventionally requires that apertures be formed in the sides of the door to accommodate door knob shanks, lock cylinders, thumb turns and the like. Mortise locks and double locks in particular employ a wide variety of aperture arrangements, often requiring two or more apertures on each side, and are not, therefore, readily installed in doors that have been cut to provide apertures for different locks. Nevertheless, because of their advantageous operational features, it is sometimes desired to use mortise or double locks as replacement equipment. If the expense of replacing the entire door is to be avoided, it is often necessary to install a U-shaped shield over the edge of the door in the region of the lock. This shield covers any unused apertures, at the same time strengthening the door and providing an attractive, convenient push plate.
The strengthening feature of the shield is particularly important because a mortise or double lock typically allows only a thin portion of the door to remain on either side, and it is, therefore, advisable to install a shield even when there are no unused openings to be covered. Shields also permit a mortise or double lock to be installed in doors made of steel and other hard to work material by cutting a simple rectangular notch that extends completely through the door instead of making a mortise cut or a more conventional double lock cut.
Only limited use has been made of shields for mortise or double locks because the variety of aperture arrangements has so far effectively prevented mass production. A primary objective of the present invention is to provide such a shield that is readily adaptable for use with many different locks, mortise and double locks in particular, and can, therefore, be manufactured in economical quantities.